Figure 16: Balloon and float chambers in pseudoplanktic forms. All specimens from the Gulf of Aqaba, Red Sea, Recent. SEM graphs.
A-B: Cymbaloporetta sp. Lateral views of dissected specimens. Note tubular infolds of the float chamber canalizing the hatching from the umbilical cavity to the preseptal space under the apertures of the balloon chamber (arrows). C-D: Tetromphalus bulloides (d'Orbigny). Lateral views of dissected and intact specimens in their pseudoplanktic stage. E-G: T. bulloides in its benthic stage, showing open umbilicus, lateral, umbilical (ventral) and spiral (dorsal) views.
a: aperture; bch: balloon chamber; flch: float chamber; fol: folium; u: umbilicus.